On August 25, 2017, Hurricane Harvey made landfall near Houston, Texas, leading to unprecedented but variable levels of flooding and secondary effects?including short- and long-term displacement, loss of employment, loss or damage to possessions, disruption of routine, and damage to neighborhoods?throughout the region. The hurricane occurred roughly two-thirds through an in-progress clinical trial, the Houston Home- Based Integrated Intervention Targeting Better Asthma Control (HIITBAC1) for African Americans, which began enrollment January 8, 2015 and exited its last enrollee on January 28, 2018. The study enrolled 263 participants and represents a group of individuals?low-income African-American adults with asthma?who are disproportionately vulnerable to the effects of flooding and other disasters. We subsequently received a R21 Disaster Research Response (DR2) award, and re-enrolled 75 of 107 the HIITBAC1 participants who exited within the 12 months before Harvey, i.e., between August 25, 2016 and August 24, 2017. All 75 received an extensive clinical and home exposure assessment post-Harvey, largely replicating the HIITBAC1 exit assessment. A blood specimen was collected at the HIITBAC1 baseline visit and at the HIITBAC2-HH assessment. We have pre- and post-Harvey banked blood for 66 of 75 individuals. Roughly 12 months after the post-Harvey assessment, we conducted a phone-based follow-up (N=64). The initial planned analyses of both HIITBAC1 and HIITBAC2-HH (the short name of the R21 study, with HH = Hurricane Harvey) studies have been completed. In addition to the 75 HIITBAC2-HH participants, 50 HIITBAC1 participants were still in the intervention phase the year before Harvey and exited after Harvey. On these 50, we have pre- and post- Harvey data as well. Together, we have 125 participants with pre- and post-Harvey data. The proposed administrative supplement intends to refine and expand the research questions addressed in the parent grant, leveraging three key strengths of the HIITBAC1 and HIITBAC2-HH studies. In particular, we propose to (1) extend our longitudinal follow-up to a fourth time point, approximately three years after the hurricane; (2) analyze the pre- and post-Harvey banked blood for fungal and bacterial infectious load, using three primers and polymerase chain reaction techniques; and (3) expand our examination of the role of spatially referenced neighborhood influences on resilience, asthma control, quality of life and healthcare utilization post disaster. We will also examine the association of speciated airborne mold counts in each of the HIITBAC2-HH homes and the corresponding fungal footprint of the patient living in that home. Key outcomes being assessed include asthma control, asthma quality of life, emergency department visits over the previous 12 months, and posttraumatic stress. The additional aims of the supplement build on an unusually rich dataset of vulnerable asthmatics on whom we have extensive pre- and post-Harvey data, addressing key gaps in our understanding of chronic disease, social vulnerability and disasters.